POULPE 



273 



PRISM 



Domesticated birds reared for eating: ducks, 



fowls, geese, turkey, &c. 

 Poulpe. [The French name ; Gk. polypous, 



many footed. ]=Octopus, g.v. 

 Pound, (pound). [L. pondus, weight.] 1. A 



weight. P. avoirdupoise=I6 ounces=7000 



grains. P. Troy=l2 ounces=5760 grains. 



2. A term of value=.20 shillings. 

 Pouter, (pou'ter). A variety of the pigeon, 



of which the breast is 



usually prominent. 

 Power, (pow'er). [Pou~ 



voir, the French word.] 



1. In arithmetic, the 

 continued multi plica- -s~ 

 tion of a number by :? 

 itself, gives the various ; 5 

 powers of that number. 

 The second power = 

 Square = The number 

 multiplied by itself; 



third power=Cube, &c. Pouter Pigeon. 



2. Capacity for doing work, as steam-power, 

 water-power, &c. Horse P., v. Horse. P. 

 loom: a loom moved by steam, water, <fec. 



Prsecoces,(pre-k6'sez). [L. prrecox, premature.] 

 Owen's term for a sub-division of birds, in- 

 cluding ground and water birds, as poultry, 

 ducks, &c. 



Prsemolar, (pre-mo'lar). [L. pros, in front of; 

 molares, grinders.] Bicuspid : the molar 

 teeth which are preceded by milk molars. 



Praesepe, (pre-se'pe). [The Latin name.]= 

 Beehive : a small nebulous group of stars, 

 in Cancer, v. Star clusters. 



Prairie, (pra'ri). [The French word.] A largo 

 plain: used especially of the vast plains of 

 N. America, cf. Pampas. 



Prase. A green variety of quartz. 



Prasiolite, (pra'zi-6-lit). [Gk. prasios, green; 

 lithos, a stone.] A mineral, chiefly silicate 

 of aluminum, magnesium, iron, &c. 



Pratt's theory: of the crust of the Earth. 

 That the elevations and depressions are 

 caused by unequal contractions in cooling. 



Prawn, (prawn). A small crustacean animal, 

 resembling the shrimp 

 =Palaemone. 



Precession, (pre-sesh'un.) 

 [L. 2'<xcedo,l go before.] 

 P. of Equinoxes: the 

 movement of the equi- 

 noctial points along the Prawn. 

 ecliptic ; which occassions an earlier recur- 

 rence of the equinoxes, v. Equinox. 



Precipitate, (pre-sip'i-tat). [L. prcecipito, least 

 down.] Solid matter chemically separated 

 from a liquid in which it has been dissolved. 

 Red P.: binoxide of mercury. White P.= 

 Chlorideof mercury and ammonia, v. Fusible. 



Prehnite, (pren'it). [Named after the dis- 

 coverer.] A minei-al substance, chiefly silicate 

 of alumina and lime, crystallising in rhombs. 



Presbyoptic, (pres-bi-op'tik). [Gk. presbys, 

 old; Optic, q. v.]= Longsighted, v. Presbytism. 



Presbytism, (pres'bi-tizm). [Gk. presbys, old.] 

 =Longsight: when the focus of the eye is 

 farther off than usual, aud only distant ob- 

 jects are distinctly seen. 



Pressirostres, (pres-si-ros'trez). [L. pressus, 

 flattened; rostrum, beak.] Plovers, bustards, 

 &c. : birds with long wings and compressed 

 beaks, forming a sub-division of Grallatores. 



Pressure gauge = Manometer, q.v. 



Primary, (pri'ma-ri). [L. primus, first.] P. 

 acids: organic acids in which one equivalent 

 of hydrogen is replaced by one of an alcoholic 

 radicle. P. alcohols = Ordinary alcohols= 

 Wood spirit, in which one equivalent of hy- 

 drogen has been replaced by one of methyl, 

 ethyl, &c. P. coil, v. Ruhmkorff's coil. P. 

 colours: red, yellow, and blue: v. Spectrum. 

 P. diamides: in which one-third of the hy- 

 drogen is replaced by an organic radicle. P. 

 monamides : in which one equivalent of hy- 

 drogen is replaced by an organic radicle. P. 

 rocks, v. Primary rocks. 



Primary rocks=Palseozoic : now applied to 

 all rocks older than Secondary: originally 

 given to all crystalline and unfossiliferous 

 formations, upon the hypothesis that they 

 were the oldest. 



Primates, (prl'mats). [L. primus, first.]=: 

 Man, apes, monkeys, and lemurs: a division 

 of Mammalia marked by a discoidal deciduate 

 placenta, a movable thumb, and incisor teeth 

 being never more than four in each jaw. 



Prime, (prim). [L. primus, first.] P. meridian: 

 that from which longitude is measured; in 

 Great Britain, that of Greenwich. P. numbers: 

 those that, like 19, 37, &c., are not divisible 

 by any whole number greater than 1. P. ver- 

 tical: a celestial great circle passing through 

 the east and west points and the zenith. 



Primitive, ( prim'i-tiv ). [L. primus, first.] 

 P. light: any one of the seven primary 

 colours of the spectrum. P. rocks: a name 

 given to granite and other crystalline rocks 

 upon the theory that they are the oldest rocks. 



Primordial zone. Term used by M. Barraude 

 for rocks in Bohemia, corresponding in part 

 to Cambrian rocks, and in which he believed 

 the first animals to have appeared. 



Primrose, (prim'ros). [L. primus, first; Rose, 

 <j.v.]=: Primula, q.v. 



Primula, (pri'mu-la). [L. primulus, first.], An 

 herb: the type of Primulacese. P. elalior= 

 Oxlip. P. veris- Cowslip. P. vulgaris= 

 Primrose: named from flowering early. 



Primulaceae, (pri'mu-la-se-e). [Primula, q.v.\ 

 Prim- worts: herbs, with beautiful fragrant 

 spring flowers, belonging to Cortusales. 



Principle, (prin'si-pl). [L. principium, begin- 

 ning.] A general term for any fundamental 

 constituent. Organic P. : substances of com- 

 plex chemical character, containing nitrogen, 

 and forming the characteristic constituents 

 of various vegetable and animal tissues. 



Printers' ink, Congealed linseed oil and 

 lamp black. 



Prism, (prizm). [Gk. prisma, splitting.] 

 A solid bounded by two 

 parallel plane surfacesand 

 a number of parallelo- 

 grams ; a transparent 



body, such as glass or rock jT~ 



salt, having regular sur- 



faces, two of them being Prisms. 



